Switch operating and resetting mechanism for alarm station



H. K. NANSEL.

Aug. 4, 1964 SWITCH OPERATING AND RESETTING MECHANISM FOR ALARM STATION www/Mmm www ab @y /M M Filed March l2, 1962 w, ma, Sfjw #LM ATTORNEYS.

United States Patent O 3,143,611 SWITCH PERATING AND RESETTING MECHA- NlSM FOR ALARM STATION Harold K. Nansel, Waverly, Nebr., assignor to Notifier Corporation, Lincoln, Nebr., a corporation of Nebraska Filed Mar. 12, 1962, Ser. No. 178,831 4 Claims. (Ci. 24W-61.62)

The present invention relates in general to electrical alarm systems, and i-t deals more particularly with socalled pull boxes designed to be actuated for the purpose of initiating an alarm.

Devices of the kind in question commonly have been :referred to as break stations in the past, by reason of being so designed as to require the breaking of a glass window or other frangible component in order to initiate an alarm. While this insures that the station, once tripped, cannot be reset except by authorized personnel capable of replacing the broken component, the person who initiates the alarm may sometimes be exposed to injury `from the broken glass fragments; moreover the Very existence of such fragments poses special problems in particular installations, for example in mental and penal institutions where broken glass can be a potential weapon or potential instrument for self-inflicted injury.

It is the object of the present invention to overcome these and other shortcomings of existing break stations, while retaining all of their operational advantages.

More specifically, it is my aim to provide an inexpensive and reliable station which is neat and attractive in appearance; which is easy for even the most inexperienced person to `operate -for the purpose of initiating an alarm but which does not invite mischievous operation; which presents no mental or physical hazard to the person desiring to operate the station; which is trouble free and very reliable in operation; which has no glass, either exposed or concealed, and does not depend upon the breaking thereof for its operation; which when once tripped to initiate an alarm cannot be reset except by authorized personnel; and which nonetheless can be reconditioned for future operation quickly, easily and without replacement of any broken parts.

Other and further objects of the invention, together with the features of novelty whereby the objects are achieved, will appear in the course of the following description.

In the laccompanying drawings which form a part of the specification and are to be read in conjunction therewith, and in which like reference numerals are employed to indicate like parts of the various views:

FIG. 1 is a front elevational view of my improved alarm station showing same in closed or nonoperative condition;

FIG. 2 is a cross-sectional view taken approximately along the line 2-2 of FIG. l -in the direction of the arrows;

FIG. 3 is an elevational view corresponding to FIG. l, but showing the station in open or operative condition; and

FIG. 4 is a cross-sectional view taken along the line 4 4 of FIG. 3.

Referring more particularly to the drawings, my improved alarm station has a box-like receptacle adapted to be secured to a wall or other suitable support 12 by means of screws 14 extending through holes in the rear of the receptacle. The front of the receptacle is covered by a stationary plate or base member 16 which is secured in place by screws 18 extending through holes in the plate into lthreaded bosses 10a and 10b provided in the interior of the receptacle.

Associated with base 16 is a swingable cover 20 having a closed position (shown by solid lines in FIG. 2) in which it forms with said base an enclosed space 22. The cover -is a channel-shaped member having integral vertical side flanges 20a and 20h between which the base 16 is received, these flanges forming opposite sides of -the enclosure 22. As may best be appreciated from FIGS. 3 and 4, base 16 is a gener-ally rectangular upright plate having along its upper and lower edges anges 16a and 16h which are bent forwardly as shown to form the top and bottom of the enclosure when the cover occupies the closed position `illustrated in FIG. 2.

The bottom flange 16b has `a pair of integral laterally extending trunnions 16C received lin aligned journal holes 20c in the opposite side flanges of cover 20, whereby the cover is hinged to base 16 to swing about a horizontal axis at the bottom of the enclosure, said axis being parallel to the stationary base or back plate 16.

Within receptacle lll is a conventional push button 24 hav-ing a hollow supporting barrel 24a which extends through a hole in plate 16 so that the push button end yof the plunger 26 is within the aforementioned enclosure. The exterior of the barrel is threaded and is secured in place by nuts 28 on opposite sides of plate 16. As is well known to those familiar with such switches, they are self-contained units having a biasing spring which urges the plunger or push button 26 outwardly toward the position illustrated in FIG. 4. When cover 2li is closed, it bears against the end of the push button and depresses same against the tension of the spring as shown in FIG. 2, but unless it is forcibly depressed in this fashion, the push button always will occupy its FIG. 4 position.

Switch 24 may either be of the normally open or of the normally closed type, the choice depending upon lthe nature of the alarm circuit to be controlled by the switch. In Ithe former case, the contacts within the switch housing are effective to complete an electrical connection between leads 32 and 34 whenever the push button is depressed (FIG. 2) Iand to interrupt said connection whenever the push button is released (FIG. 4). In the latter case the effect of the switch is just the opposite, that is to say, its contacts complete a connection between conductors 32 and 34 whenever the push button is released (FIG. 4) and they open that connection whenever the push button is depressed. The switch contacts by which the connection is thus opened or closed, as the case may be, have not been illustrated in the drawings because, as previously mentioned, the switch itself is entirely conventional and well known to those versed in the art.

Slightly above its center, cover 20 contains a hole for receiving the hollow supporting barrel 36 of a con ventional cylindrical lock. The barrel is secured in place and held against rotation in the hole by means of a nut 38 threaded on its inner end, this being tightened down to draw the integral annular llange on the opposite end of the barrel tightly against the outer face of the cover, clamping it securely. A latch finger 4t? keyed on the inner end of the lock cylinder 42 to turn therewith is anchored in place by a nut 44.

It will be understood that cylinder 42 normally is held against rotation in its supporting barrel by means of the lock mechanism, and when thus locked the latch linger 40 extends downwardly toward the hinged lower end of the cover as shown in FIG. 2; however, the cylinder is provided with a key slot 42a at its exposed end, and insertion of a proper key 46 releases the lock mechanism, permitting the cylinder to be turned by the key whereby, referring to FIG. 3, the latch finger 40 is turned from its locked position (shown in solid lines) to its unlocked position (shown in dotted lines).

Above push button 24, the stationary base plate 16 is dished to form a concave pocket or indentation 16d for receiving the threaded end of cylinder 42 and its nut 44 f Y 3 when the cover is closed as illustrated in FIG. 2. Immediately below this indentation there is a spring catch or keeper for the latch finger 40; this comprises a relatively strong spring coil 50 which is stretched so as to be under axial tension between the apertured supporting ears 52a' of the bracket 52, the latter being fastened to plate 16 by rivets 54 or the like.

Ears 52a extend outwardly only a small distance from the face of plate 16 and, when cover 20 is opened (FIGS. 3 and 4), spring 50 is not only parallel torplate I6 but spaced therefrom by a distance slightly smaller than the thickness of finger 40. Accordingly with the cover closed and latch 4t) in its locked position behind the spring as illustrated in FIG. 2, the spring is stretched slightly against its owntension due to the medial portion thereof being forced slightly farther away from plate le, and under this condition spring 50 cooperates with latch 4l) to hold the cover 2t) closed. It will be noted that the level of the horizontal axis of the spring is just below the lower extremity of the latch linger.

When closed, the upper edge of cover 2t) projects above the level Vof flange 16a, forming a handhold 20d which may be gripped with the fingers for the purpose of pulling the cover outwardly and downwardly toward the position shown in dotted lines in FIG. 2. It is in this way that members of the general public are intended to initiate an alarm. Being in the path of latch 40, spring 50 naturally resists outward movement of the cover quite strongly, but application of a substantial outward force on the hand grip 20d Will cause the latch to distend the midportion of the spring first outwardly and then downwardly as shown by dotted lines so that the latch can pass thereover. As soon as this occurs, the cover 20 will swing down freely to the position illustrated in FIGS. 3 and 4, releasing the spring biased push button 26 and thus causing switch 24 to initiate the alarm.

If an attempt now is made to forcibly reclose cover 2t) while latch di) still is in the position shown in FIG. 4, the latch will engage spring t) and push the medial por tion rearwardly until it engages plate 16, whereupon the spring can move no farther. Because of its closeness to the plate (FIG. 4), the permissible rearward stretching of the spring is too small to permit any substantial downward displacement of the medial section and latch 4t) therefore cannot pass over the spring under this condition. In other words, cover when once opened cannot be relatched in closed condition except by authorized service personnel having a proper key such as 46.

ponents contained in the enclosure 22 are covered and concealed when door 20 is closed.

I have shown the receptacle 10 mounted on the surface of the wall l2 by means of screws 14;, but in some installations it is desirable to wholly recess the receptacle in the wall, whereby only the base member 16 and the cover 20 project beyond the surface of the wall. This decreases the distance which the unit extends into the room and makes the installation somewhat more attrae# tive, while at the same time leaving sufficient space behind the hand grip Ztlb to permit forcible opening of the cover in the manner heretofore described. If receptacle 10 is recessed in the wall, the conductors 32, 34 extending from the receptacle through the opening 10a will be concealed within the wall. Whether the wiring which connects my station to the balance of theV alarm system is concealed within the wall or exposed outside the Wall, it usually is desirable that it extend through conventional conduit terminating at the opening 10c, in keeping with good electrical wiring practices.

From the foregoing it will be seen that my invention is one well adapted to attain all of the ends and objects hereinbefore set forth together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the appended claims. Y

Inasmuch as various possible embodiments of the invention may be made without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be inv "i terpreted as illustrative and not in a limiting sense.

Having thus described the invention, I claim: l. In a device of the character described, an enclosure having a normally closed cover and a stationary wall Y generally parallel to said cover when the cover is closed,

By means of this key, latch 4t) can be turned 90 to the i* position shown by dotted lines in FIG. 3. When the cover now is swung closed, latch itl will clear spring and, upon passing thereover, will seat against the flat portionrof plate I6 just outside the margin of the indentation 16d, after which rotation of the key 90 will cause the latch once more to swing downwardly and engage behind the distal side of the spring as shown in FIG. 2. Doing this, of course, depresses push button 26 and thus resets switch 24 to condition the station for the initiation of another alarm.

When cover 20 is closed, key 46 can also be employed to unlatch it so that access to the interior of space 22 can be gained without the need for pulling on the hand grip 20d and overcoming the resistance of spring catch 50 in the fashion described hereinbefore. To do this, it is only necessary to turn latch 4l) through 90 by means of the key, thereby disengaging the latch from spring 50 and enabling it to pass freely over the spring as the cover is moved from closed to open position. Opening of the cover not only permits manual actuation of the push button 26 as desired for testing the operation of the alarm circuit, but also exposes screws 18 so that plate 16 can be removed from box l0 and switch 24 can be repaired or replaced should this be necessary. It will be obvious ofcourse that all screws and all means of access to the interior of my alarm station and the coma pair of stationary spaced apart supports Within said Y enclosure, a helical spring coil having its opposite ends connected to the respective supports so that said spring is carried by and between said supports under axial tension, said coil being parallel to said stationary wall spaced therefrom by a distance less than the diameter of the coil, a member mounted on said cover in a position such that it is disposed crosswise of said spring in spaced relation thereto when said cover is closed, a latch carried by said member and having an end portion normally engaging the side of said spring nearest said stationary wall, means for applying manual force to said cover in a direction urging same away from said wall, said spring being effective to resist movement of said latch away from said wall but being distendable under the influence of said latch to permit said latch 'to pass thereover upon said application of 'force to the cover, said stationary Wall preventing said latch from distending and passing over said spring in the opposite direction, whereby said latch cannot be forcibly restored to normal position after being forcibly removed therefrom, key controlled means for at times shifting said latch relative to saidV member so that said latch can pass freely over said spring without distending it, an electrical switch, an actuating member for said switch controlled byrsaid cover to operate the switch responsive to opening of the cover.

V2. In a device of the character described, an enclosure comprising a base and a normally closed cover,.an electrical switch, an actuating member for said switch controlled by said cover to operate the switch responsive to opening of the cover, a pair of spaced apart supports on said base, a helical spring coil having its opposite ends secured to the respective supports, said coil being under axial tension between the two supports and its axis lying in a plane generally parallel to said cover when the latter is closed, a latch mounted on said cover in a position such that opening of the cover carries said latch across said plane in one direction and closing of the cover carries the latch across said plane in the opposite direction, the medial portion f said spring normally engaging the end of said latch when said cover is closed whereby said spring yieldably resists movement of the latch in said one direction, means including said spring preventing return movement of said latch to normal position over the same path traveled by the latch in leaving said position against the tension of said spring, and key controlled means for at times shifting said latch in a plane parallel to said cover thereby to permit said latch to travel across said first plane without engaging said spring.

3. In a device of the character described, a stationary member having a spring biased push button thereon, a movable member hinged to said stationary member and swingable toward said push button to engage and depress same against the tension of the spring, means normally holding said swingable member in said last mentioned position thereby to maintain said push button depressed, said means comprising a latch on one of said members cooperating with a spring catch on the other member, said catch being yieldably displaceable by said latch to a position out of the path of the latter when an external force of predetermined magnitude is applied to said swingable member urging it away from said push button, whereby said swingable member is forcibly movable away from the push button, means effective upon retrograde movement of said latch along the same path to prevent displacement of said catch out of said path thereby to defeat attempts to forcibly restore said member to normal position, key controlled means for at times releasing said latch to permit movement of said swingable member toward or away from said push button at will without displacement of said catch, and an electrical switch mechanically coupled to said push button so that it is open 6 or closed depending upon whether said push button is or is not depressed.

4. In a device of the character described, an enclosure comprising a base and a cover hingedly mounted thereon for movement between open and closed positions, a latch on the cover cooperating with a catch on the base to normally hold the cover in closed position, said catch comprising a pair of stationary supports on the base and a helical coil spring having its opposite ends secured to the respective supports, said spring being under axial tension and its medial portion lying in the path of the end of said latch whereby a forced opening movement of said cover causes said latch to deflect the spring in one direction and pass thereover, while a closing movement of the door tends to deflect said spring in another direction, said base having means restricting deflection of said spring in said last direction to an amount too small to permit said latch to pass thereover, whereby said spring normally prevents forcible closing of said cover, key controlled means for at 'times shifting said latch relative to said cover so that upon opening and closing movements of the cover the latch travels freely over said catch without engaging same, an electrical switch, and an actuating member for said switch controlled by said cover to operate the switch responsive to opening of the cover.

References Cited in the file of this patent UNITED STATES PATENTS 2,210,512 Terjesen Aug. 6, 1940 2,822,451 Holmes Feb. 4, 1958 2,830,143 Koopman Apr. 8, 1958 2,957,719 Hafstad Oct. 25, 1960 3,012,803 Hafstad Dec. 12, 1961 3,037,801 Hafstad June 5, 1962 

1. IN A DEVICE OF THE CHARACTER DESCRIBED, AN ENCLOSURE HAVING A NORMALLY CLOSED COVER AND A STATIONARY WALL GENERALLY PARALLEL TO SAID COVER WHEN THE COVER IS CLOSED, A PAIR OF STATIONARY SPACED APART SUPPORTS WITHIN SAID ENCLOSURE, A HELICAL SPRING COIL HAVING ITS OPPOSITE ENDS CONNECTED TO THE RESPECTIVE SUPPORTS SO THAT SAID SPRING IS CARRIED BY AND BETWEEN SAID SUPPORTS UNDER AXIAL TENSION, SAID COIL BEING PARALLEL TO SAID STATIONARY WALL SPACED THEREFROM BY A DISTANCE LESS THAN THE DIAMETER OF THE COIL, A MEMBER MOUNTED ON SAID COVER IN A POSITION SUCH THAT IT IS DISPOSED CROSSWISE OF SAID SPRING IN SPACED RELATION THERETO WHEN SAID COVER IS CLOSED, A LATCH CARRIED BY SAID MEMBER AND HAVING AN END PORTION NORMALLY ENGAGING THE SIDE OF SAID SPRING NEAREST SAID STATIONARY WALL, MEANS FOR APPLYING MANUAL FORCE TO SAID COVER IN A DIRECTION URGING SAME AWAY FROM SAID WALL, SAID SPRING BEING EFFECTIVE TO RESIST MOVEMENT OF SAID LATCH AWAY FROM SAID WALL BUT BEING DISTENDABLE UNDER THE INFLUENCE OF SAID LATCH TO PERMIT SAID LATCH TO PASS THEREOVER UPON SAID APPLICATION OF FORCE TO THE COVER, SAID STATIONARY WALL PREVENTING SAID LATCH FROM DISTENDING AND PASSING OVER SAID SPRING IN THE OPPOSITE DIRECTION, WHEREBY SAID LATCH CANNOT BE FORCIBLY RESTORED TO NORMAL POSITION AFTER BEING FORCIBLY REMOVED THEREFROM, KEY CONTROLLED MEANS FOR AT TIMES SHIFTING SAID LATCH RELATIVE TO SAID MEMBER SO THAT SAID LATCH CAN PASS FREELY OVER SAID SPRING WITHOUT DISTENDING IT, AN ELECTRICAL SWITCH, AN ACTUATING MEMBER FOR SAID SWITCH CONTROLLED BY SAID COVER TO OPERATE THE SWITCH RESPONSIVE TO OPENING OF THE COVER. 